Means for balancing stresses in rail joints



B. G. BRAINE- 4 MEANS FOR BALANCING STRESSES IN RAIL JOINTS.

APPLICATION FILED SEPL24, I920- Patented Feb. 14; 1922.

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,B. G. BRAINE.

MEANS FOR BALANCING STRESSES IN RAILIJOINTS.

APPLICATION FILED SEPT.24, 19-20.

Patented Feb. 14, 1922 2 SHEETS-SHEET 2.

lwuentoz UNITED STATES PATENT OFFICE BANCROFT G. BRAINE, OF MONTGLAIR, NEW JERSEY, ASSIGNOR TO THE RAIL JOINT comm, on NEW YORK, N, Y.,

A CORPORATION OF NEW YORK.

MEANSFOR BALANCING STRESSES IN RAIL JOINTS.

Specification of Letters Patent.

Patented Feb." 14, 1922.

Application filed September 24, 1920. Serial No. 412,557.

To all whom it may concern:

Be it known that I, BANCROFT G. BRAINE,

This invention relates to rail joints and particularly to a novel modification in the distribution of metal in a rail joint bar to better balance stresses therein, thereby reducing the liability to rupture under service conditions.

Because of the requirement of adapting the designof a joint bar to a fit with the rail I and also to meet certain other service conditions, some of the fibres which are most remote from the horizontal neutral axis are not scientifically disposed from the standpoint of strength, being therefore susceptible of rupture. And in, certain types of bars, the

supplementaldistribution of metal produces an unduly high ratio of disproportion between the section modulus of the top chord of the bar and the section modulus of the strains imposed upon these extreme top- Accordingly, the present invention contemplates an improvement for deflecting the load stress to a point below the inadequate area of metal, above referred to, and in the case of the head of the bar leaves practically all of the fishing surface at the top of the bar to serve as'a support for the underside of the rail head, but practically eliminates it as a factor in the theoretical calculation of the strength of the bar.. In other words, the

invention proposes to establish or locate a desirable area of metal bearing a proper relation to the distribution of metal through-- out the bar so as adequately to meet the reuirements of maximum stresses imposed on the head of the bar, thus better safeguarding the bar against the opening of cracks or sud: den'rnpture. v

The foregoing general object may be conveniently carried into execution by so altering the original distribution of-metal at the top of the bar, as in effect, to establish a top bar embodying t in the theo its underlying principle may chord composed of fibres uniformly distant from the neutral axis of the bar. That is to say, the invention contemplates the formation of a construction to eliminate excessive strain in the small area at the top of the bar section by modifying the rail head-engaging part of the bar to convert it primarily into" what may be termed a bearing filler in sup porting enga ement with the rail head, and at the same time utilizing it to transmit the load stresses more directly to that portion of the bar wherein the fibres are scientifically disposed to more adequately meet the re-- quirernents of the maximum stresses.

W1th the above and other objects in view which Wlll morereadily appear as the na-,

drawings, in which Figure 1' is a erspective view of a joint iie present improvements.

Figure 2 is a perspecti've'view of the continuous type of joint bar embodying the present improvements.

Figure 3 is a erspec side of the bar 5 own in Fig. 2.

Figure 4 is a dia rammatic view illustratof t e present invention.

imilar re erence numerals designate correspondingparts throughout-the several figuresof the drawings.

Primarily, the invention provides a joint bar structure having means for a better balancing of the useful metal so that the bar will more adequately meetthe requirements of the maximum stresses. Also, in its application to the top part or head of the bar to provide means for deflectingthe load stress to a oint below the less useful metal located the arthest from-the neutral axis of the bar.

" Although the invention is useful in connection with the ordinary ty of angle bar,

applied with equal facility to bars of the continuous type with a view of establishing a-more useful ratio between the section modulus of thetop of the bar and the section modulus of the bottom of the bar. And, itis to be understood that the present invention includes within its scope the modification of either 'ture of' the invention is better understood tive view of the outthe head of the joint bar, or of both the head and base portion of the bar; in the latter case, particularly in a bar of the continuous type, wherein as a rule, there isan unduly high ratio of disproportion between the section modulus of the top of the bar andthe section modulus of the bottom of the bar.

By reference to Figure 1 which shows a standard type of angle bar 1,'it will be observed that the head portion 2 thereof, having the rail engaging face 3, is provlded at intervals with fibre interrupting kerfs, produced by transversely notching or cutting through the remote fibres, as indicated at 4. The said kerfs serve to breakup the continuity of the fibres in the rail engaging portion of the head 2, thus making in effect at the extreme top of the bar a plurality of relatively independent fillers forming rallen aging portions 5.

The said kerfs 4 are preferably carried to a depththat substantially defines an upper limit of the useful area of the fibres of the bar which are uniformly spaced from the neutral axis of the bar, and therefore break up the continuity of the fibres of the metal which are most remote from the neutral axis of the bar. These remote fibres theoretically no not enter into the strength of the bar and merely serve the function of a hearing filler to support the head of the rail, thus simply transmitting load stresses fromth'e rail to that portion of the fibres of thehead which are adequate to withstand said stresses. The kerfing of the rail contacting surface of the bar to the extent indicated, resulting in the formation of the relatively separate portions 5, alsoadds to the flexibility of the mass of inert metal at the top of the head of the bar to facilitate the passing of the rail wave motion through the joint.

By reference toFigure 4, which diagrammatically illustrates the theory of the invention, the purpose andefiect of the transverse kerfing or notching of the head of the bar will be more readily apparent. In the portion of the bar designated as X the fibres of the metal, by reason of their varying distances from the neutral axis (NA) of the bar have no direct relation to a scientific distribution of the metal which enters into the calculation of the strength of the bar. However, the portion of the metal designatedas Y indicates an area in. wh'ichthe fibres are uniformly distant from the neutral axis of the bar, and therefore sustain equal bending strains. In other words, as all of the fibres in the area Y have equal stresses brought upon them, they are better able to withstand the strain imposed thereon than the fibres in the area X wherein the fibres most remote from the neutral axis receive greater strains than others and are therefore more likely to give away and start the bar head to crack. The boundary between the areas X and Y, in the example shown, therefore constitutes the de th of the kerf in the head of the bar, and t is means of determining the depth of the kerfs may be of course applied to bars of any design or typae by suitable calculations.

y reference to Figures 2 and 3 it will be observed that the invention may be readily adaptedto bars 10 of the continuous type, wherein the head portion 11 is transversely kerfed or notched as at 12 while the base flange 13 may also be provided at its inner edge with the kerfs or notches 14 and a relatively large intermediate kerf or notch 15, while the outside toe portion of the base may also be provided with a central kerf or notch 16. That is to say, to improve the proportionate ratio between the section modulus of the top of the continuous bar and that of the bottom of said bar, it is proposed to notch the base at various points so as to make a more nearly balanced section. By this arrangement the neutral axis is necessarily raised, thus increasing the individual fibre strain in the elements of the base and materially reducing those in the head, the moment of inertia being also reduced, making the bar less stifl' while the modulus remain approximately the same. Also this arrangement locates the neutral axis of the bar much nearer the bolt holes which is an additional advantage. a In the case of the continuous bar, the notching of the base as at 14 and 15 is especially advantageous since the effect thereof is toproduce a more flexible fitting of the bar to the rail, particularly in the base, thus taking care of slight differences in the rails without gripping the base too tightly. And, in the case of the relatively wide notches 15 and 16 located in the central portions of the base of the bar it is pointed out that these notches materially reduce the transverse sectionalarea of the base throu h the midsection of. the bar, thereby reduclng the superabundance of the tensile strength of the base, as compared with that of the head, to a point where the improved head construction will be adequate to resist rupture because of the more reasonable balancing of the top and bottom sections of the bar adjacent to the abutting rail ends.

Itwill of course be understood that the invention is particularlysusoeptible of embodiment in all rolled rail joints, and in carrying the same into effect the formation of the kerfs or notches in the head and base of the bar may be carried out in any suitable manner.

From the foregoing it is believed to be apparent that the novel feature of cutting through the inadequate areas of either the head or base of a joint bar to create a modified port on or area which will more adequate y meet the requirements of maximum stresses, is particularly advantageous since it eliminates cracking of the bar and renders the same more flexible and therefore better adaptable to the carrying of the wave motion in the rails through the joints.

Without further description it is thoughtthat the many features and, advantages of the invention will be readily apparent to those skilled in the art, and it will of course be understood that the invention is susceptible of embodiment in any and all types of joint bars, and that the details of the execution may be varied within the scope of the appended claims, without departing from the apparatus and spirit of the invention.

1. A method of confining the stresses in rail joints which consists in removing from the bar inadequate areas of metal remotely located from the neutral axis to thereby defiect the load stress to broader areas of metal below said inadequate areas.

2. A joint bar including a head portion having its rail engaging face transversely notched, the depth of said notches being de fined by the limit of the area of unbroken fibres of the metal uniformly distant above the neutral axis of the bar.

3. A continuous rail joint bar having metal-eliminating notches in its top edge and in the inner edge of its base-member.

4. A method of confining and balancing stresses in a rail joint bar which consists in interrupting the fibres of the metal of the bar located most remote from the horizontal neutral axis thereof.

5. A method of confining and balancing the stresses in a rail joint bar which consists in forming metal removing notches or kerfs at intervals in the bar located most remote from the horizontal neutral axis thereof.

6. A method of balancing the stresses in a rail joint bar which consists in forming notches in the bar transversely of the direction of the fibres of the metal therein.

7. A method of balancing the stresses in a rail joint bar which consists in forming notches at intervals in the areas of metal located most remotely from the horizontal neutral axis of the bar and in which the fibres are at non-uniform distances from the said neutral axis.

In testimony whereof I hereunto affix my signature in the presence of two witnesses.

BANCROFT G. BRAINE.

WVitnesses:

E. K. KnRsHNnR, C. A. DISBROW. 

